Rotary gas-engine



(No Model.) v2 lSheets-Sheet 1.

L.' GATHMANN. ROTARY GAS ENGINE.

No. 570,470. "Patented Nov. 3, 1896.

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(No Mdel.)

No. 570,470. Y PatenteaNw; s, 1896.

UNITED STATES' PATENT` OFFICE.

LOUIS GATHMANN, OF CHICAGO, ILLINOIS, ASSIGNOR TO DANIEL Y. MOMUL- LEN,OF SAME PLACE, JAMES B.

MCMULLEN, OF NEW YORK, N. Y.,

GEORGE \Y. MOMULLEN, OF PICTON,` CANADA, AND DAVID S. MCI/IUE LEN- ANDROGER B. MCMULLEN, OF EVANSTON, ILLINOIS.

ROTARY GAS-ENGINE.

SPECIFICATION forming `part of Letters Patent N o. 570,470, datedNovember 3, 1896.

` Application filed June 1,1895- Serial No. 551,427. (No model.)

To all wiz/m t may concern:

- Be it known that I, Louis GA'rHMANN, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain `new and useful Improvements in Rotary Gas-Engines; and

I do hereby declare the following to be a full,

clear, and exact description of the invention,

such as will enable others skilledin the art 1o to which it appertainsto make 'and use the same.

This invention relates to a novel construction in a rotary gas-engine ofthat class employing an explosive charge as the source of power andpropelling medium, as distinguished from engines wherein compressed air,steam, and analogous gases are employed as the propelling medium,namely, such gases exerting power by expansion due to the re- 2o leaseof pressure thereon.

The object of my invention is to provide an engine of the kind abovepointed out which combines certain features which simplify theconstruction and produce an effective engine.

The invention consists in the features of construction and combinationsof parts hereinafter fully described and specifically claimed.

In the accompanying drawings, illustrating my invention, Figure l is aside elevation of an engine constructed in accordance with my invention,with certain parts omitted for convenience of illustration. Fig. 2 is aside 3 5 elevation taken from the opposite side, with certain partsomitted for convenience of illustration. Fig. is a vertical longitudinalsection taken on the line 3 3 of Fig. 5. Fig. 4: is an elevation, on anenlarged scale, of the 4o governor for controlling the supply of oil orgas. Fig. 5 is a horizontal transverse section taken on the indirectline 5 5 of Fig. 3. Fig.

6 is a vertical longitudinal section of a modified constructionembodying my invention and illustrating the engine constructed with asingle valve.V Fig. 7 is a side elevation of another modifiedconstruction embodying my invention wherein the valves are carried bythe rotating piston. Fig. 8 is a vertical longitudinal section of thesame. Fig. 9 is a frag- 5o mentary section of the valve and valve-seat,taken on the line 9 9 of Fig. 6. Fig. l0 is a detail top plan View ofthe projecting block at the left of Fig. 3, in which the air and oilsupply passages are situated. As before stated, it is the object of myinvention to simplify the construction of a rotary gas-engine and at thesame time to provide for obtaining the maximum of energy from thepropelling medium.

The invention relates and is confined, as above pointed out, to rotaryengines in which an explosive charge is employed as the source of power,and is operated by a continuous series of explosions, and is thereforedistinctly v of a different class from engines which employ air, steam,or gas acting by expansion after pressure is relieved, for my engineacts upon a different principle, and the same conditions do not apply toboth classes of en- 7o gines. By certain no-vel features of constructionin a rotary gas-engine acting under this principle, namely, a series ofexplosions, I am enabled to combine in a small compass an effective andpowerfulV engine. To attain this result, I have provided a cylinder anda revoluble piston situated within the same, and between which thechamber or channel wherein the explosive force of the gas exerts itselfis situated.

The piston is supported by a shaft mounted in bearings outside of thecylinder and does not come in contact with the cylinder. The said pistonis set within the cylinder and fits nicely therein with a small Vspaceintervening 8 5 between the relatively movable parts to avoid friction,while the bearings for the pistonshaft are arranged in the curved sidearms, hereinafter described. The curvature of said side arms providesfor suiiicient elas- 9o ticity to compensate for the expansion of theworking parts of the engine caused by the variations in temperaturetherein. I also provide a construction whereby the explosion of the gasis made as effective as possible, that is to say, I provide for thecleansing of the chamber or channel between the cylinder and pistonafter each explosion to remove all spent and inert gases entirely beforea new explosive charge is admitted, so that in each explosion the fullforce of the explosive medium is obtained. By combining in a rotarygas-en gine these and other features, all of which are specificallydescribed hereinafter7 IV am enabled to provide a simple and powerfuldevice.

Referring now to said drawings, 1 indicates the base-plate, and 2 and 3upright side plates extending upwardly from said baseplate and whichsupport the cylinder t of the engine. lVithin said cylinder a piston 5is situated, and is carried by a shaft 0, that extends on both sides andis mounted in bearings 7. These bearings 7 are supported by curved armsS, rigidly secured to the side plates 2 and 3 and to said bearings 7.The piston 5 is about the same width as the cylinder, and its diameteris slightly less than the cylinder, so that it can revolve freelytherein, that is to say, the adjacent faces of the piston and cylinderdo not come in contact with each other, and, therefore, when the engineis working, the friction ordinarily generated between these twoprincipal working parts is obviated entirely, and it is obvious thatthere is less loss of power in the engine. The piston is guidedlaterally by two rings or gaskets 0, secured to the cylinder andoverlapping the outer edge of the piston. It will be understood, ofcourse, that in an engine of this kind heat is generated; also that theteinperature varies, and, consequently, the size of the parts variesslightly. In view of this fact, and to preserve strictly the position ofthe piston within the cylinder, that is to say, to prevent the pistonfrom binding and causing friction, I employ the curved arms 8 forcarrying the bearings 7. These arms are of equal length and size and aresufficiently elastic to compensate for the expansion and contraction ofthe working parts of the engine, and thus under all circumstances tomaintain the bearings in their proper position concentric with thecylinder.

The cylinder is, of course, provided with induction and exhaust ports,described hereinafter, and between the cylinder and piston a chamber orchannel is formed wherein the exploded gas is conned. This chamber canbe formed by making a groove in the face of either cylinder or pistonand mounting the valves on either of these parts, as shown. Across thegroove extend the abutments for forming these power-chambers,while theside walls of the grooves are inclined or beveled, as shown in Fig. 5,to receive the beveled valve, all as described hereinafter.

Referring now to Figs. 1 to 5 of the drawings, the said cylinder fl isprovided at diametrically opposite points with inductionports 10, toadmit the propelling medium to the cylinder. The said ports 10communicate with a suitable source of supply,which in the instanceillustrated consists of air-pipes 11 and gas or oil pipes 12, and theadmixture of gas and' airis adapted to enter the cylinder and to bethere exploded by any suitable means of ignition coming from a suitableignition-recess. A constant supply of air under constant pressure isadmitted to the airpipes 11, and this supply of air should be in excessof the theoretical requirements of the engine, and itcan be attained bythe employment of a double-actin g air-pum p or from any other efficientsource of supply. The said piston 5 and shaft 6 are hollow, and in thesides of said piston are a series of perforations 13, while the hollowshaft within the piston has a series of perforations 14, so that acooling medium can be forced through the shaft and piston to cool theformer. As before stated, the said piston-'fits within the cylinder and1s held in place by the rings 9 and the shafts and bearings, and I haveprovided on the face of said piston a valve seat or groove havinginclined or beveled walls converging` toward the center of the pistonand at diametrically opposite points I arrange transverse abutments 15,which divide this valve-seat into two chambers 1G.

-I make the transverse abutments 15 wider than the induction-ports 10.In this way, while the abutments are passing the induction-ports thesaid ports will be closed for a moment and the mixture is conned to themixing-chamber. The admixture will thereby be more complete, the area ofpossible leakage much reduced, while at the saine ti me the pressurewithin the mixing-chamber is inomentarily increased, so that when thecharge is admitted to the explosion-chamber after the passage of theabutments the desired,

pressure and resulting force of the explosion will be more uniformly andeconomically maintained.

Although in this description I refer to two diametrically oppositelylocated inductionports, abutments, valves, and eduction-ports, yet itwill be understood that the number can vary, as found most efficient.

In the rear of the induction-ports 10 are the eduction or exhaust ports17. Located between the ports 10 and 17 are the valve-openings 18,formed in the cylinder, and through which the valves 19 extend and enterthe valve -seat or chambers 16 in the face of the piston 9. The endportions of said valves entering said valve-seat or chambers 16 arebeveled on their sides to conform to the contour of the inclined sidesof said valve-seat. It will be noted, also, that said valves do not comein contact with the valve-seats, but that a slight space intervenes thatprevents friction between these parts, as between the cylinder and thepiston above described. By thus arranging the principal parts so thatthey work without friction I am enabled to save a great amount of powerusually lost, due to this cause, and therefore make the engine moreeffective.

Although there is a slight space between the cylinder and piston andbetween the IOO IIO

IIS

valve and piston in Figs. 1 to G, and between valves and cylinder inFigs. 7 and `8, or, stated broadly, between the valves and the partbetween which and the valve there is relative rotation, yet the space isso small that there is no appreciable escape of the products of theexplosion, or such as to diminish the effective force of the explosion,as has been demonstrated.

I employ a mechanism, of course, formoving the valves out of the path ofthe abutments as the latter approach the valves and to move said valvesinwardly after said abutments pass by, and the saidA valves19 arelocated and arranged so that the back pressure of the propelling mediumcomes against the endof` the valve and the strain or pressure thereon isnot against the piston but upon the pivot of the valve itself, and inthe instance shown this is accomplished by arranging the valveapproximately tangential to the piston, so that the pressure is receivedby the pivot, and in this manner the `piston is relieved of pressure. Ithus avoid the friction that usually takes place between V4the valves ormovable abutments and' cylinder or piston. Consequently, byobviatingcthis friction I am enabled to save a large amount of power, asWell as prolong the life of the parts of theengine.`

I do not claim in this application the construction of the valves andpiston, nor the means for operating said valves, as this is claimed inanother application for patent filed by me in the United States PatentOffice December 31, 1894, and Serial No. 533,544.

Communicating with the induction-ports 10 are the passages 20, foradmitting the propeiling medium. These passages 2OA communicate with theair-supply pipe 11 through openings 21, controlled by check-valves 22,while the oil or gas supply pipe 12 communicates with the passage 2Othrough an opening 23, controlled by a valve 24, operated at intervalsby the engine.

The valves 19 are hung on pivots 25, extending between the uprightplates of the engine, and these pivots 25 extend through the side plate2 and are provided with arms or levers 2G, whose free ends are locatedin the path of projections or arms 27, fastened to the piston, as

shown in Fig. 1. The valves are normally held at the inward limit oftheir movement and resting in their seats 16, and the projections 27 areso located with reference to the abutments 15 that they engage thelevers 26 to move the valves outwardly when the abutments approach thesamesand to allow them to reseat after the abutments pass by.

It will be `seen that the ends of arms 27 strike the ends of arms 2G andturn the pivots 25` to move the valve outwardly, and that the valves arereturn ed to their normal position by springs 26?", that press againstfeet 2Gb, secured to thearms 26; i

The s upply of air is controlled automatically in accordance with therelative pressure on ried by the piston.

opposite sides of the Vcheck-valves 22, but the supply of oil isregulated bythe movement of the'pistonand controlled by a governorcarried thereby, as will now be described.

The valves 24 are connected, through the intermediacy of links, with avibrating lever 28, mounted upon. plate 3 of the engine, and an arm 29is fastened to said lever and projectsv downwardly in the path of acam-disk 30 car- The cam-disk 30 has two projections 31 so located thatthey strike arm 29 at the moment it is desired to open the valves 24,while the cam-disk 30 is movable upon the hub 32 of the piston and uponwhich it is mounted. The cam projections 31 are beveled on their innersides, so that while the disk stands at the inner limit of its movementthe arm 29 will be moved to the full extent of the projection; yet whenthe disk is moved outwardly by the governor the extent of move- `ment ofthe arm 29 decreases proportionately to the inclination or bevel of thecam projections 31, and thus opens the valves 24 to a lessl extent. Thesaid governor is mounted upon the hub 32 and consists of projections 33,upon which .are pivoted bell-crank levers 34, weightedat one end and attheirother ends engaging a groove in 35 in a hub projection 36 of thecam-disk. Springs 37 are held by pins 38 mounted upon hub 32, and serveto hold the bell-crank levers 34 at the inner limit of theirmovement.`In this way it will be "seen thatthesupply of oil can beregulated and isof the engine becomes excessive the governor will serve to open thevalves to a less extent and regain their former position as the speedapproaches normal.

It will be understood that there is a constant supply of air controlledby the pressure on check-valves 22, and that although the oil is underpressure also, yet it is controlled by the piston and is admitted whilethe air is on, and I put the oil under greater pressure than the airthat a small quantity can be quickly injected at the proper moment.

IOO

`controlled automatically, and that if the speed IIO The operation ofthe engine is as follows:

In Fig. 3 the parts are shown in about the position they occupy justafter an explosion has taken place and the abutments 15 are travelingfrom the induction-port 10 to the exhaust-port 17, that is to say, thevalves 'controlling the air and oil supplies have opened and closed, theoil-valve 24 being closed` by the mechanism heretofore described and`the air-valves 22 being closed. by the excess of pressure between the`cylinder and said valves. When the abutments 15 reach the exhaust-ports17 the active and useful force from the exploded gases has about ceased,and it will be noted that when the abutments pass the exhaust-ports thepressure within the cylinder decreases considerably, owing to theopening of thisport, and therefore the pressure Within the air-pipellbeing maintained will overcome the pressure within the cylinder, andtherefore open the air-valve 22 remaining will be blown out through theforebeen accomplished.

I yobtain* from allowing this fresh charge of airv valve-opening I8, butas soon as the abutment passes by the valve and the valve closes thefresh air is then retained within the cylinder, and as soon as theabutment passes the induction-port IO the supply of oil or gas isadmitted and the admixture becomes ignited from the ignition-recess, andthus supplies another propelling charge tothe cylinder, and so on.

It will be seen from the foregoing description that by expelling fromtheI cylinder all the inert and spent gases and cleaning the cylinder,so to speak, the next charge has greater force and power than if thesespent gases remained and were admixed with the fresh charge, andtherefore I am enabled to ina more economical manner than has hereto-Another advantage to pass through the cylinder after each explosio'n-isthat the piston and cylinder is cooled off to a certain extent, that isto say, the excessive heat usually present is reduced and equalized to acertain extent by this charge of fresh air passing through the heatedparts and the premature explosion of the mixed gas and air effectuallyprevented.

In Fig. 6 I have shown a modified construetion embodying my invention,which consists in making the cylinder with one inductionport, oneexhaust-port, and one valve, and in making the piston with only oneabutment. The construction and operation of the former will be obvious.I have also shown in said Fig. G a safety or relief valve formaintaining the supply of oil at an even pressure, which consists of avalve-chamber 3f), situated between the pipe l2 and the valve 24, whilea passage 40 leads from said valve-chamber 39 to the oil-passage 22%.Above the passage 40 a relief-passage 4l leads from said valvechamber89, and within the valve-chamber 89 a valve 42 is situated and carries astein 43 passing out through the upper end of the valve-chamber andprovided with weights 44, which can be increased or diminished inaccordance with the pressure to be maintained. The normal pressure upontheoil is sufficient to lift the valve 42 above the passage 40, and thuspermit the oil to flow to the oil-passage 23, but it will be seen thatunder an abnormal pressure within the pipe 12 the valve 42 will beraised still higher and above the reliefpassage 41, `and thus relievethe pressure by permitting the excess of oil to flow through passage 4lback to the oil-tank. lVhen the pressure again becomes normal, the valve42 recovers its former position, as will be seen. In this way it isapparent that a regular pressurey can be maintained to feed the oil inthe desired quant-ity.

In connection with Fig. G is illustrated a form of oil-tank that couldbe employed, and consisting of a tank 47, communicating by means ofpassage 12 with the engine. In this passage l2 is arranged a pump 49,for forcing the oil, and the relief-passage also flows into this tan-k,as shown.

In Figs; 7 and 8, I have shown still another modified constructionembodying .my invention wherein the chambers to receive the propellingcharge are formed by making a groove in the inner face of the cylinderinstead of in theouter face' of the piston, as abovedescribed. In thisconstruction the valves I9 are situated and pivoted within the hollowpiston and proj ectthrou gh valve-openings 1S therein into the groove orchambers 16 ofthe piston, practically the reverse of that abovedescribed. The pivots 25 of the valves project through the side wall ofthe piston and arev provided with arms 2G, that engage projections 46,fastened to the side of the cylinder to cause the valvesto rock on theirpivots when they approach and retire from the abutments. Inv otherparticulars the construction is similar and the engine works in thesamemanner.

It will be seen, therefore, that I provide a rotary gas-engineto bepropelled by successive explosions wherein the rotating part or pistonisentirely surrounded or inclosed by a cylinder, and between whichpiston and cylinder the explosion-chamber is situated, but thatth'episton and' cylinder are not in contact with each other and rotatewithout friction.

I claim as my inventionl. In a rotary gas-engine wherein explo'- sivecharges are employed as a source of power, a cylinder, and a piston ofless diameter than said cylinder situated and supported within thesameand capable of rotation therein without contact with the saidcylinder, substantially as described.

2. In a rotary gas-engine, a passage in communication with theinduction-port and with a means for supplying air under constantpressure, and withk a means for intermittently supplying gas 0r oil at apressure greater than that of the air, and a valve in the air-supplypassage constructed and arranged to be controlled by differences ofpressure in the airsupply pipe and the passage to the inlet-port,

and for the purpose set forth.

In a rotary gas-engine, a cylinder having induction and exhaust ports, arevoluble piston situated within said cylinder and having a chamber orvalve-seat and abutments, a valve passing through an opening in saidcylinder and adapted j to enter said chamber or valve-seat, and situatedbetween said exhaust and induction ports, means for opening and closingthe valve before and after the passage IOO IOS

IIO

`of an abutment, an exploding device, and

means constructed and arranged to supply to the induction-port air andgas or oil before explosion and air after explosion, substantially asdescribed.

4. In a rotary gas-engine, a cylinder having induction and exhaustports, a revoluble piston situated within said cylinder, and having avalve-seat and abutment, a valve passing through an opening in saidcylinder and entering said valve-seat, in the gas or oil supply passage,and situated between said exhaust and induction ports, means i'oropening and closing the valve before and after the passage of anabutment, and an air-supply, and a gas or oil supply communicating withsaid induction-port, a valve for controlling the admission of gas or oilto said inductionport operated by means of said piston, and acheck-valve situated in the air-supply passage, substantially asdescribed.

5. In arotary gas-engine, a cylinder having induction and exhaust ports,a revoluble piston situated within said cylinder, and having avalve-seat and abutment, a valve passing through an opening in saidcylinder and entering said valve-seat, and situated between said exhaustand induction ports, an air and gas or oil supply communicating withsaid induction-port, a valve for controlling the admission of gas or oilto said induction-port operated by said piston, and means for admittingair to said induction-port after the abutment passes said exhaust-portand until the explosion occurs, substantially as described.

6. In a rotary gas-engine, the combination with a cylinder havinginduction and exhaust ports, of a piston rotatably mounted therein,valves pivotally mounted upon one of said parts and adapted to entervalve-seats, said valve-seats being formed in the other of said partsand having inclined side walls and transverseabutments, and said valveshaving inclined ends adapted to enter said valveseats, with devices foradmitting the propelling charge and for operatin g the valves,substantially as described.

7. In a rotary gas-engine, the combination with a cylinder havinginduction and exhaust ports, of a piston rotatably mounted therein andhaving a groove or chamber and transverse abutments, said abutmentsbeing wider than said induction ports, and valves for said groove orchamber, substantially as described.

S. In a rotary gas-en gine,wherein explosive charges are employed as asource of power, a cylinder and a piston coperating therewith, one ofsaid parts having an explosion-chamber and the other part having aclearance extending into the explosion-chamber, and said parts rotatingwithout frictional contact and a valve or movable abutment adapted to beprojected at regular intervals into the explosion-chamber to confine theexplosive force, substantially as described.

In testimony whereof;l I affix my signature in presence of twowitnesses.

LOUIS GATHMANN. lVitnesses:

' RUDOLPH WM. Lorz,

HARRY` COBB KENNEDY.

